Octamethylcyclotetrasiloxane, commonly referred to as D4, is a cyclic silicone compound. In the cosmetic industry, D4 was once widely used due to its skin-softening properties, providing a silky texture to hair, and helping products dry quickly after application. However, recent toxicological studies have highlighted the serious risks this active ingredient poses to human health and the environment, prompting pharmaceutical regulatory agencies worldwide and in Vietnam to tighten usage regulations.
Toxicology and Health Risks
Toxicological studies indicate that D4 causes liver hypertrophy and hepatocyte proliferation in rodents. D4 disrupts the endocrine system, interferes with ovulation, reduces embryo implantation capacity, increases the rate of post-implantation loss, and exhibits weak anti-estrogenic activity. Although some toxicity mechanisms may be specific to animals, the risks of disrupting the endocrine system and interfering with ovulation still subject D4 to strict monitoring by the medical community.
Due to these hazards, D4 has been included in the list of prohibited substances in cosmetics in many countries and regions, including the European Union (EU) and ASEAN member states.
Bioaccumulation and Environmental Devastation Risks
Not only does it harm humans, but D4 is also a major ecological threat due to its low biodegradability and very high bioaccumulation potential. Experimental data have recorded the bioconcentration factor (BCF) of D4 reaching up to 12,400 in certain fish species, demonstrating its dangerous accumulation in the aquatic food web. Because of its low water solubility, this substance tends to strongly adsorb to organic matter in soil, sewage sludge, and river and marine bottom sediments, leading to long-term ecological consequences. Furthermore, traces of D4 have even been detected in the blood of adults, pregnant women, and breast milk in numerous surveys worldwide.
Regulations on the Recall of Violating Products
According to the latest notices and decisions from the Drug Administration of Vietnam (Ministry of 000Health), cosmetic products containing the D4 ingredient are considered in violation of cosmetic formulation regulations. These products must be suspended from circulation and thoroughly recalled nationwide to ensure maximum safety for consumers.
The recall list encompasses a diverse range of products, from perfumes, skin creams, and shampoos to makeup products. Regulatory authorities require business and import establishments to proactively review the ingredient lists on product labels. If the presence of D4 is detected, the unit must immediately cease distribution and coordinate the destruction process in accordance with current regulations.
Recommendations for Consumers and Healthcare Professionals
Consumers need to be cautious by carefully checking ingredient lists and immediately discontinuing the use of cosmetics containing D4 or those on the recall list. Concurrently, healthcare professionals should proactively update their knowledge regarding D4 toxicity to guide the community in identifying risks. Any abnormal reactions when using suspected cosmetics must be reported promptly to regulatory authorities to strictly comply with the Ministry of Health’s guidelines and protect public health.
MsC. Le Viet Anh – Deputy Director of the Center for Support & Continuing Education